Relay



E. BRAUER Dec. 12, 1939.

RELAY Filed Dec. 5, 1936 Z W VVW w w w o .1. a 5 @F I a n m r, L w 2 Wmm a /a/ 3 2 w m fi In yen for:

Patented Dec. 12, 1939 UNITED STATES PATENT OFFICE RELAY Ernst Briuer,Volgtsdorf in- Biesengebirgc, Germany 6Claims.

This invention relates to a dynamic relay.

It is known to construct relays in such a manner that their operation isbrought about by the motion of a coil disposed between the poles of '5 amagnet and rotatable about an axis positioned outside the center of thecoil or entirely outside the coil. objection that the adjustment of therelay depends upon the position thereof and that the relay to 10 aconsiderable extent is subjected to shocks and impulses. Furthermore,the natural vibration of the moved part is usually too slow.

The present invention eliminates these drawbacks by providing a relaycomprising a magnet and a movable coil secured to a movable partsupported at or near its center of gravity. The movable part need not bedisposed in a mechani cally highly sensitive pivot, but may be arrangedon leaf springs, whereby at the same time the period of naturalvibration is shortened in a very simple manner.

By way of example, the present invention is illustrated in theaccompanying drawing, in which Figures 1, 2 and 3 are diagrammaticviews, partly 26 in section, of three different embodiments of theinvention.

As shown in Fig. 1, I is a permanent steel magnet of the type used inloudspeakers. In the annular gap between the two poles of the magnet I30 a coil 2 is provided which is secured to a frame 4, made for instanceof aluminum sheet metal, which is partly recessed and covered by aninsulating disk II. The frame I is rockingly supported by the leafsprings I! only one of which 88 is shown and which may serve forsupplying current to the coil 2, in which case they are insulated andattached to the plate 3 and connected to a plugcontact ID. Theinsulating disc ll supports leaf springs 4i carrying the contacts 8.

40 The springs ll may be made for instance of thin strips of bronze.when current passesthrough the coil 2, the entire system supported bythe leaf spring It will be moved, so that the contacts 8 can perform thenecessary circuit closmg operations with respect to the fixed contactscrewsl. While. the drawing shows only one movable and one fixedcontact, several such contacts I, I may be provided side by side in suchmanner that they can be adjusted from above and are therefore located onthe same side of the movable part but on the opposite sides of itsfulcrum. The movable member 2, 4, is balanced by the counterweight 8, sothat it will not move relative to the relay when the position of thelatu terisaltered. llisaleafspringtendingtopress This arrangement isopen to the the frame 4 upwardly to the right, the tension of whichspring can be varied by means of a screw 5.

Measurements have shown that with such a relay at a current energy of10" to 10'- watts 5 contact pressures of sufilcient magnitude andcorresponding safety in operation can be obtained.

When several contacts 6, I are employed and arranged on both sides ofthe bearing of the 1. frame 4 on the leaf springs i3, a particularadvantage can be attained according to the invention by one pair ofcontacts 6, I being adjusted to the right and left somewhat more looselythan the others, the two contacts acting, respectively, 15 as movableand fixed contact. The ends of the coil are then connected with the moreloosely adjusted contacts, so that the coil will be shortcircuited, asthese contacts make connection. If contact is made with such energy thatthe danger 20 of chattering of the frame arises, after the movablecontacts have made connection the more loosely adjusted contacts arealso connected and thus the coil 2 is momentarily short-circuited- Thecurrents induced therein momentarily consume the kinetic energy, andframe 4 is not thrown back.

The construction shown in Fig. 2 aims at rapid contact making. Thecontacts i2, ll, corresponding to the contacts 6, I of Fig. l, are ar-30 ranged a great distance from the center of the oscillating motion offrame 4, whilst the coil 2 itself makes only very small motions in thegap of the magnet I. The frame 4 is entirely pressed for instance ofinsulating hard paper and secured again to the insulating plate 3 by thesupporting leaf springs l3. Balancing is effected by the weight I. Theconductors 42 for the contacts l2 are guided near the center ofoscillation of the frame 4' and then pass as flexible, conductors to 0the stationary portion of the relay. In case of continuous currentactuation the spring It like the spring I! in Fig. 1 acts to returnframe 4;

Experience has shown that with such relays at an energy rate of a fewthousandths of 2. watt 4 in case of alternating currents up to about1000 hertz, clean response, of the relays can be attained and that atthese frequencies the relayon a movable and a fixed contact perfectlyperforms four operations per oscillation or 4000 50 operations persecond. It is advisable to utilize thaspringiness of the bronze stripsll support-' ing the contacts l2 for throwing back the frame aftercurrent in the coil 2 ceases. The natural frequency of these bronzestrips is so great that II it is far beyond 1000 hertz and thereforedoes not affect the operation of the relay. Preferably, however, theoscillation of the bronze strips is further damped by means of rubberbufiers 48, as indicated in Fig. 3. s

According to the present invention, these relays are further soconstructed that the magnet can be separated from the otherself-contained structure. For example, Fig. 2 indicates that the magnetcan be separated from the system by the loosening of the screws It. Thisaffords the advantage that the magnet can be magnetized separately andthe danger of dust, particularly iron filings, entering the gap duringthe mounting is eliminated. The gap and the whole upper portion of therelay are closed dusttight by a. paper tube 36 shown in Fig. 2 while thecap 41 closes only the upper portion down to the plate 3. In this waythe cap is not loaded with the great weight of the magnet which mayserve as a convenient handle for manipulating the relay, and theconnections, such as the plug pins I0 in Fig. 1, can freely extendoutwardly.

According to Fig. 3, the invention further provides that the actuatingcurrent flows parallel or in series with the coil of an electromagnet25. The contact 49 with the countercontact 3| is attached to a straightleaf spring 24 and the contact 50 with the countercontact 30 to the bentleaf spring 28 which, owing to initial tension, compresses the rubberbuffer 48. The frame 23 is supported by the leaf springs H3. Thecountercontacts 30 and 3| are disposed in the cap or casing 32 coveringthe entire relay. The conductors of the contacts lead to the plug plate5!. The armature 26 of the electromagnet 25 is secured to frame 23, andthe dimensions are chosen so that at the moment contact is made thedistance of the electromagnet from its armature becomes very small. Itis known that the pull between magnet and armature increasesconsiderably with the decrease in distance, so that the initial motionof frame 23 is effected almost exclusively by the pull of the coil 2whilst towards the end of the motion the effect of the electromagnetmakes itself more and more felt and finally expresses itself in aconsiderable increase of contact pressure. The armature 26 serves alsofor balancing frame 23. The principal magnet 22 is in this case also anelectromagnet which is energized by a separate source of current.

It is further possible to provide several windings in the coil 2, two ofthem, 20 and 2|, being shown 'in the drawing, thereby to produce adifferential action. For example, the coil 2| mayconstitute theoperating coil of the relay, and the coil 22 (Fig. 2) may be connectedwith the short-circuiting contacts BI, 62 and 60, 63. In that event, thesame damping action of the frame 4 is attained, as when the operatingcoil itself is short-circuited by one of these contacts, although in asomewhat lesser egree. In this case, however, there is the advantage,that the intensity of the current in the short-circuiting conductors cannot excessively increase, in case the outer resistance of the circuitcomprising the current generator is slight. Instead of shortcircuit abalanced damping can of course be attained by the insertion of an outerresistance.

Fig. 3 further shows the retarding device for retarding in an adjustablemanner the making and breaking of contract. It is known to employ asbrake for the movable parts of a relay an air piston which tightly movesin an airtight cylinder. The form of relay shown does not require aspecial piston and air cylinder, the body of the coil 2 being simplyclosed on top, for instance by a paper sheet 33. The core of the magnetthen acts as stationary piston and the body of the coil as a movablecylinder. To regulate the retardation air is admitted through the bores3'! and 40 which can be closed more or less by the screw 35.

I claim:

1. A dynamic relay, comprising a casing, a magnet having between itspoles an annular gap, a coil extending into said gap, a frame outside ofsaid magnet supporting said coil and forming together therewith amovable member, resilient means supporting said movable member,cooperating contacts on said frame and said casing, and means for sobalancing said frame that its position relative to the contacts on thecasing is varied only upon said coil being acted upon by electromagneticforces, but is not varied by mechanical'forces acting on said casing.

2; The combination as specified in claim 1,

including additional contacts for short-circuiting said coil aftercompletion of the operation of the relay.

3. The combination as specified in claim 1, including an auxiliarywinding connected with said coil, and additional contacts forshortcircuiting said coil after completion of the operation of therelay.

4. The combination as specified in claim 1, in which all the contactsare positioned on one side of said frame.

5. The combination as specified in claim 1, including an iron .armatureprovided on said frame, an iron core connected with said casing,

and an electromagnetic coil on said iron core being electricallyconnected with said first-mentioned coil and receiving the operatingcurrent.

6. A dynamic relay, comprising a casing, a magnet having between itspoles an annular gap, a coil extending into said gap, 'a frame outsidesaidmagnet supporting said coil and forming together therewith a movablemember, a leaf spring supporting said movable member, coop-- ERNSTBRAIJER.

